High inrush current produced when equipment is turned on may result in damage to electrical devices as well adjacent apparatus. In addition, for example, personal injury may even occur. For example, a large power drill can break the wrist of a user. A safe and cost effective way to reduce inrush current is to use an inrush current limiter (Surge Limiter), which is a special type of negative temperature coefficient (NTC) thermistor.
Typically, an NTC thermistor's resistance drops logarithmically as its body temperature increases. The function of a Surge Limiter is to first block the inrush current and then effectively remove itself from the circuit. The limiter blocks the incoming current spike by offering a relatively high resistance at turn on.
Typical resistance ranges are from 0.25 ohm to 220 ohm, depending on the amount of protection desired. As current flows through to the Surge Limiter, the resistance drops to as low as 0.01 ohm, which functionally removes it from the circuit.
Typically, a thermistor is connected in series with a load. It is operationally desirable to limit the time in which the resistance of the thermistor is high. Thus, it is highly desirable to quickly cooldown the thermistor after the load has reached steady-state conditions. One approach would be to use a fan or blower to quickly cooldown the thermistor. Such an approach is not particularly appealing because such an approach would add complexity to the apparatus as well as the need for a power source to drive the fan or blower.
The present apparatus relies on a heat exchange apparatus having characteristics to dissipate the heat.
From the above, it is therefore seen that there exists a need in the art to overcome the deficiencies and limitations described herein and above.